首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   76篇
  免费   1篇
废物处理   4篇
环保管理   3篇
综合类   41篇
基础理论   4篇
污染及防治   19篇
评价与监测   4篇
社会与环境   2篇
  2022年   2篇
  2021年   2篇
  2020年   1篇
  2019年   1篇
  2018年   3篇
  2017年   2篇
  2015年   3篇
  2014年   3篇
  2013年   5篇
  2012年   2篇
  2011年   3篇
  2010年   1篇
  2008年   2篇
  2007年   4篇
  2006年   1篇
  2004年   1篇
  1999年   2篇
  1981年   1篇
  1980年   2篇
  1978年   1篇
  1977年   2篇
  1976年   1篇
  1975年   2篇
  1972年   1篇
  1971年   3篇
  1970年   3篇
  1969年   1篇
  1966年   2篇
  1963年   1篇
  1958年   1篇
  1952年   1篇
  1942年   1篇
  1941年   1篇
  1940年   2篇
  1939年   2篇
  1938年   5篇
  1937年   2篇
  1936年   1篇
  1934年   1篇
  1929年   2篇
排序方式: 共有77条查询结果,搜索用时 15 毫秒
21.
The concentrations of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) were determined in river sediments collected at the Ave river basin (Portugal) to obtain a general classification scenery of the pollution in this highly polluted region. Multivariate data analysis techniques of clustering, principal components and eigenvector projections were used in this classification. Five general areas with different polluting characteristics were detected and several individual heavy metal concentration abnormalities were detected in restricted areas. A good correlation between the overall metal contamination determined by multivariate analysis and metal pollution indexes for all sampling stations was obtained. Some preliminary experiments showed that the metal concentrations normalised to the volatile matter content in the sediment fraction with grain size <63 microm seems to be an adequate method for assessing metal pollution.  相似文献   
22.
23.
24.
25.
26.
27.
28.
Seafood mislabeling is common in both domestic and international markets. Studies on seafood fraud often report high rates of mislabeling (e.g., >70%), but these studies have been limited to a single sampling year, which means it is difficult to assess the impact of stricter governmental truth‐in‐labeling regulations. We used DNA barcoding to assess seafood labeling in 26 sushi restaurants in Los Angeles over 4 years. Seafood from 3 high‐end grocery stores were also sampled (n = 16) in 2014. We ordered 9 common sushi fish from menus, preserved tissue samples in 95% ethanol, extracted the genomic DNA, amplified and sequenced a portion of the mtDNA COI gene, and identified the resulting sequence to known fish sequences from the National Center for Biotechnology Information nucleotide database. We compared DNA results with the U.S. Food and Drug Administration (FDA) list of acceptable market names and retail names. We considered sushi‐sample labels that were inconsistent with FDA names mislabeled. Sushi restaurants had a consistently high percentage of mislabeling (47%; 151 of 323) from 2012 to 2015, yet mislabeling was not homogenous across species. Halibut, red snapper, yellowfin tuna, and yellowtail had consistently high (<77%) occurrences of mislabeling on menus, whereas mislabeling of salmon and mackerel were typically low (>15%). All sampled sushi restaurants had at least one case of mislabeling. Mislabeling of sushi‐grade fish from high‐end grocery stores was also identified in red snapper, yellowfin tuna, and yellowtail, but at a slightly lower frequency (42%) than sushi restaurants. Despite increased regulatory measures and media attention, we found seafood mislabeling continues to be prevalent.  相似文献   
29.
Journal of Material Cycles and Waste Management - Finding innovative solutions to manage waste and to expand the production of biofuels are some of the current challenges. Pulp and paper sectors,...  相似文献   
30.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号